Could someone please check my work

2. The boundary of [0, 11) U (11, 14) is: 0 [0, 11] {0, 11} {0, 11, 14} Explain: Let S = [0, 11) U (11, 14) . O E S and O E N(0; E) . to tradeuggs hing vispound Since N(0; E) n S * 0 andN(0; E) n(R\\ S) # 0, then by definition 3.4.3 for the boundary of S' , 0 is in the boundary of S . God if hepoly ed up bige er ? not , 9 2 and Also, 11 & S but 11 E N(11; E) . Since N(11; E) n S * 0 and N(11; =) n(R\\S) # 0, then by definition 3.4.3 for the boundary of S , 11 is a boundary point of S . Also, 14 & S but 14 E N(14; E) . Since N(14; E) n S # 0 and N(14; E) n (R\\S) # 0, then by definition 3.4.3 for the boundary of S , 14 is a boundary point of S . Therefore, the boundary of S' is {0, 11, 14}